Preheat the oven to 425°F (218°C).
Pat the 1.5 lb salmon filet dry with paper towels. Line a baking sheet with foil for easy cleanup and place the salmon on the prepared sheet.
Zest 1 lemon and set the zest aside, then cut the zested lemon into wedges and set the wedges aside for serving.
In a small bowl, combine 4 tbsp unsalted butter (softened), 4 garlic cloves (minced), 1 tsp salt, 1/2 tsp pepper, 1 tbsp fresh parsley (chopped), and the lemon zest. Mix until evenly combined.
Spread the butter mixture evenly over the top of the salmon.
Bake the salmon in the preheated oven for 12–15 minutes, or until the internal temperature at the thickest part reaches 145°F (63°C).
Remove the salmon from the oven and squeeze the reserved lemon wedges over the salmon before serving.